1. Technical Field
The present invention relates to a light output control device for laser light sources used as a backlight of a display.
2. Background Art
In a laser light source device used as a backlight of a display, to reproduce correct colors, the magnitudes of respective RGB light outputs need to have specified values. Upon a normal operation, a light output from a laser light source is detected and fed back to drive unit, whereby the light output is controlled to a specified light output. This is generally called APC control.
FIG. 6 is a block diagram showing a configuration of a conventional light output control device. This light output control device includes, for the respective RGB colors, light output control unit 21, 22, and 23; semiconductor lasers 41, 42, and 43 that output lights of the respective colors; and light output detection unit 31, 32, and 33. In the conventional light output control device, APC control is performed on a color-by-color basis. For each color, light outputs from the semiconductor lasers 41, 42, and 43 are controlled by the light output control unit 21, 22, and 23 such that the light outputs from the semiconductor lasers 41, 42, and 43 detected by the light output detection unit 31, 32, and 33 match their respective light output target values. The configuration is the same for all the RGB colors and control is independently performed such that light outputs from the respective semiconductor lasers match their respective RGB light output target values which are used to obtain luminance required for a display backlight.